I think it is very common that when GMs are controlling opponents, they try to enter their mindset (immerse) and play these opponents to their best of their ability trying to make the life of the PCs as hard as possible. I believe this kind of mindset to be well known (even though not everyone apply it themselves), and for the purpose of this thread I want to introduce the term "adversarial GM stance" as a short hand to describe such a mindset.
I think this mixes too much.
1. The DMs that treat foes as just nothing NPC game tokens and the Immersive DM that treats all NPC as Characters.
2. Not all NPC, even when played immersivly will be a hard opponent: they can be anything.
Simply said, a benevolent stance would be that the GM for a short period of time can feel like he play at the same team as the PCs rather than continuously being neutral or acting as an opponent.
A typical such benevolent DM plays the whole game in this mindset....they can't witch out as that would disrupt the benevolence. Even acting neutral is 'against' the PCs and players.
At first glance the opposite of the classic adversarial stance of playing hostile NPCs - playing friendly NPCs - might seem as a good example of a situation where the GM can take a benevolent stance in the sense I am talking about here. However I find with myself that in actual play that is not the case. While there might be a hint of wanting to help the PCs in there, I do rarely immerse myself in really doing my best to come up with how the NPC can actively help the PCs in a similar way that I would immerse myself in the enemy to find good ways they can oppose the PC. Rather I am careful not to leave a more neutral stance, keeping a strong eye on the meta by taking into consideration principles like making sure the NPC is in no way outshining the PCs. For instance in tactical combat I might abstain from making the best tactical move I can see for a friendly NPC, as that might steal the PCs glory.
This is a good place to point out the above of what is a NPC here:
1. A lifeless game token that is only there to be a play part for the PCs and players
2. An immersive fictional character
The first is what you get in video games......the old wise wizard just stands outside of town and gives advice, and once you do quest X he will sell you magic potions.
The second is where the DM makes every NPC a full character. And you can already hear the echo of the complaint "that is too much work" form the Casual DMs.
As the second type, immersive DM, all my NPCs are characters. So good characters will help the PCs out to the best of their abilities....in the right situations. This does require what I call my Hard Fun stance.
Typically players think it is a great idea to have a powerful npc buddy come along. Though in my game, the NPC will outshine the stumbling bumbling PCs in seconds. While the players will sit and endless talk about "how can we attack ten goblins", my NPC can do an amazing solo combat and take all ten out while the players watch in awe.
So with the obvious candidate for "benevolent stance" excluded, can anyone think of any examples of experiencing situations in play where you have had the mindset that you really try to help the players out? Is there any context where you for instance have felt sufficiently restricted by rules (either written or self imposed) that you really felt you could bring your A-game in trying to help out the PCs? I think most have experienced an encounter where the danger level for death is so low that the constraints of the game system and stat block has allowed them to comfortably try to play the enemies of the PCs as nastily as they can think of without pulling any punches.
The BGM often helps out by not being even slightly aggressive. Having NPCs only do 'medium' attacks at best. Or much like most movies or TV shows....the foes will endlessly wait for the players to act and will never take advantage of anything.
And this even goes beyond to "no character death" or "character harm" and even to "nothing the players don't like ever".